cal/lib/slots.ts
2021-12-16 15:20:38 +00:00

71 lines
2.3 KiB
TypeScript

import dayjs, { Dayjs } from "dayjs";
import isBetween from "dayjs/plugin/isBetween";
import isToday from "dayjs/plugin/isToday";
import utc from "dayjs/plugin/utc";
import { getWorkingHours } from "./availability";
import { WorkingHours } from "./types/schedule";
dayjs.extend(isToday);
dayjs.extend(utc);
dayjs.extend(isBetween);
export type GetSlots = {
inviteeDate: Dayjs;
frequency: number;
workingHours: WorkingHours[];
minimumBookingNotice: number;
};
const getMinuteOffset = (date: Dayjs, step: number) => {
// Diffs the current time with the given date and iff same day; (handled by 1440) - return difference; otherwise 0
const minuteOffset = Math.min(date.diff(dayjs.utc().startOf("day"), "minute"), 1440) % 1440;
// round down to nearest step
return Math.ceil(minuteOffset / step) * step;
};
// eslint-disable-next-line @typescript-eslint/no-unused-vars
const getSlots = ({ inviteeDate, frequency, minimumBookingNotice, workingHours }: GetSlots) => {
// current date in invitee tz
const startDate = dayjs().add(minimumBookingNotice, "minute");
// checks if the start date is in the past
if (inviteeDate.isBefore(startDate, "day")) {
return [];
}
const localWorkingHours = getWorkingHours(
{ utcOffset: -inviteeDate.utcOffset() },
workingHours.map((schedule) => ({
days: schedule.days,
startTime: dayjs.utc().startOf("day").add(schedule.startTime, "minute"),
endTime: dayjs.utc().startOf("day").add(schedule.endTime, "minute"),
}))
).filter((hours) => hours.days.includes(inviteeDate.day()));
const slots: Dayjs[] = [];
for (let minutes = getMinuteOffset(inviteeDate, frequency); minutes < 1440; minutes += frequency) {
const slot = dayjs(inviteeDate).startOf("day").add(minutes, "minute");
// check if slot happened already
if (slot.isBefore(startDate)) {
continue;
}
// add slots to available slots if it is found to be between the start and end time of the checked working hours.
if (
localWorkingHours.some((hours) =>
slot.isBetween(
inviteeDate.startOf("day").add(hours.startTime, "minute"),
inviteeDate.startOf("day").add(hours.endTime, "minute"),
null,
"[)"
)
)
) {
slots.push(slot);
}
}
return slots;
};
export default getSlots;